package model;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.List;

public class BlogDao {
    // 1. 新增操作 (提交博客就会用到)
    public void insert(Blog blog) {
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            connection = DBUtil.getConnection();
            //构造mysql
            String sql = "insert into blog values(null,?,?,now(),?)";
            statement = connection.prepareStatement(sql);
            statement.setString(1,blog.getTitle());
            statement.setString(2,blog.getContent());
            statement.setInt(3,blog.getUserId());
            //执行sql语句
            statement.executeUpdate();

        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }
    // 2. 查询博客列表 (博客列表页)
    //    把数据库里所有的博客都拿到.
    public List<Blog> getBlogs() {
        List<Blog> blogLists = new LinkedList<>();
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try {
            //建立连接
            connection = DBUtil.getConnection();
            //构造sql
            String sql = "select * from blog order by postTime desc";
            statement = connection.prepareStatement(sql);
            resultSet = statement.executeQuery();
            while(resultSet.next()) {
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                String content = resultSet.getString("content");
                if(content.length() > 100) {
                    content = content.substring(0,100);
                }
                blog.setContent(content);
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                blogLists.add(blog);
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return blogLists;

    }
    //3.根据博客id查询指定的博客
    public Blog getBlog(int blogId) {
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try {
            connection = DBUtil.getConnection();
            String sql = "select * from blog where blogId = ?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            resultSet = statement.executeQuery();
            if(resultSet.next()) {
                Blog blog = new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                blog.setContent(resultSet.getString("content"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                return blog;
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,resultSet);
        }
        return null;
    }

    //4.根据博客id删除博客
    public void delete(int blogId) {
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            connection = DBUtil.getConnection();
            String sql = "delete from blog where blogId = ?";
            statement.setInt(1,blogId);
            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }
}
